User`s guide

2 Making Measurements
Measuring AC Voltage
38 U1273A/U1273AX User’s Guide
Figure 2-3 AC voltage with LPF display
The low- pass filter can improve measurement performance
on composite sine waves that are typically generated by
inverters and variable frequency motor drives.
WARNING
• To avoid possible electric shock or personal injury, do not use the
Low Pass Filter option to verify the presence of hazardous AC
voltages. AC voltage values greater than what are indicated may
be present when the Low Pass Filter is enabled.
• First, make an AC voltage measurement with the filter OFF to
detect the possible presence of hazardous voltages. Then, select
the filter function if required for measurement stability and
response speed.